Polyamide pigment dispersion

Abstract

An improved process for preparing pigmented drawn polyamide fibers is disclosed, the improvement being the improved processability obtained from the use of an N,N'-dialkyl polycarbonamide as a carrier polymer for the pigment dispersion.

I claim: 
     
       1. A method for improving spinning performance in a process for preparing drawn pigmented polyamide filaments comprising the steps of: a) adding to a molten fiber-forming polyamide a liquid pigment concentrate comprising from 1%-60%, based on total weight of concentrate, pigment dispersed in a polymer matrix of from 40%-99%, based on total weight of concentrate, of an N,N'-dialkyl polycarbonamide having a melting point less than about 100° C. and a number average molecular weight between 800-5000;   b) mixing said liquid pigment concentrate with said molten fiber-forming polyamide to produce a uniform blend;   c) spinning said blend into filaments; and   d) drawing said filaments.   
     
     
       2. The method of claim 1 wherein the N,N'-dialkyl polycarbonamide is selected from the group consisting of poly(N,N'-dibutylhexamethylene dodecamide and poly(N,N'diethylhexamethylene dodecamide. 
     
     
       3. The method of claim 3 wherein the N,N'-dialkyl polycarbonamide is poly(N,N'-dibutylhexamethylene dodecamide.